Led limiting resistor

[HankMcSpank]

In which case, I'd not be going dicking about with hw comparators (that said when you think about it, ADC'ing a signal and then comparing against a preset level in software is a comparator...a sw comparator), RMS to DC converters etc....just tap off some reduced AC from each element feed (obviously 5V 'peak to peak' max, but at least here when your element is only drawing 1A there'll still be 1V AC peak to peak - more than enough to work with) ...squirt the 16 tapoffs into a PIC's ADC pins (use two PICs to get around the 'not enough ADC channels' problem). Then step through each pin all sequentially, staying on each pin for long enough to ensure you capture a 'non zero' reading (note: 'zero' here being half your VCC, so for 8 bits, and a VCC of say 5V, 2.5V = 127.....so say any ADC reading less than 110 or more than 144 means there's AC present....if so move on, if not then latch a red led, then move on etc)